单选题 "I'm certainly more and more to the conclusion that Iraq has, ______ they maintained (断言) , destroyed almost all of they had in the summer of 1991 ." Blix said.

【正确答案】 D
【答案解析】关系代词as引导非限制性定语从句作maintain的宾语；在宾语从句中缺少宾语，应用what引导，故选D。